Tissue culture flasks are widely used in the laboratory for many purposes. Typically, these flasks are used to culture microorganisms or tissues in a culture medium or agar which is adhered to an interior surface of the flask. The tissues are introduced into the flask through a capped opening. The flask is re-capped and inserted into a stacking facility or chamber, such as an oven, to facilitate the growth of the microorganisms in the medium. In laboratory practice, it is quite common to arrange or stack several tissue culture flasks in a single chamber. Thus, the size of the individual flasks becomes a concern as it desirable to position as many flasks as possible in a single chamber.
Another concern in constructing tissue culture flasks is the volume within the flask which is available for accommodation of both the culture medium as well as the tissue. In order to enhance stackability of the flasks in the chamber, many tissue culture flasks are generally flat rectangular containers having a neck or opening at one end wall permitting access to the interior of the flask. The culture medium is adhered to the bottom wall of the flask. The flask may be filled with culture medium and tissue to a level approaching the bottom of the neck or opening. Thus, the usable volume of the flask is determined by the vertical distance between the bottom wall of the flask and the flask opening, since the culture medium and tissue cannot extend above the flask opening. While spacing the opening from the bottom all of the flask will increase the usable volume of the flask, it does increase the overall size (stacked height) of the flask. This reduces the number of flasks which can be stacked in a chamber. Attempts to decrease the size of the opening, in order to increase the usable volume, result in limiting accessibility to the entire bottom wall of the flask as such access is gained through the opening. Often, in certain situations, it becomes necessary to access the tissue growing in the medium on the bottom wall of the flask. It is desirable for the user to access the entire bottom surface of the flask, including the corners, with a scraper, pipette, or other instrument. Decreasing the size of the opening severely restricts the area of the bottom wall which may be accessed therethrough.
It is therefore desirable to provide a tissue culture flask having a sufficiently large opening so as to permit access to the entire bottom surface thereof without decreasing the usable volume or increasing the stacked height of the flask.